Hitherto, it has been known to provide mining methods and apparatus to control mining of product from a seam of product in the mine. One known longwall mining method involves observing infrared (IR) radiation from a fresh cut product face at a position immediately adjacent the cutter at the region where a vertical wall of cut intersects with either an upper or lower wall of cut. Such method determines either an upper or lower limit of the seam of the product in the mine by noting if there is an IR temperature increase at the intersection of the vertical cut wall and either the horizontal cut floor or horizontal cut roof. An IR temperature increase occurs when a cutter cuts into strata in the roof or floor immediately above or below the seam of the product. This is because the strata is usually harder than the production in the seam and therefore the strata heats more during the cutting process than the product. Thus, by noting an IR temperature increase at this region, one can determine the upper and/or lower limits of the seam of the product in the mine. Signals can be generated defining the upper limit or lower limit of the seam so that the mining machine can be controlled to cause the cutter to not cut into the overlying or underlying strata.
Such methods and apparatus are useful, however, such methods and apparatus do have their failings and it is possible for the overlying or underlying strata to be mined and cut with the product from time to time. This places undue loadings on the mining equipment, dilutes product content and gives rise to other production problems including an increase in dust within the mine which, in turn, affects personnel safety within the mine.